The reversals are what we call "the rollercoaster" and it can be very confusing. My W held my hand once all through dinner at a restaurant but when we got home she wouldn't talk to me at all and slept on the couch.
That's why its good not to engage when they are in monster mode -- it will pass and in the moment you only stand to make things worse.
Congratulations on your boy to be! Reconsider allowing H to participate in the naming. Rise above and be the better person here. If you don't like his choices, veto them. In the case that you DO reconcile it will be a constant reminder if you go with a name he doesn't like!
Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015